The present invention relates to a method and to apparatus for masking a portion of a motor vehicle, in order to protect said portion from the dirtying that can result from painting some other portion of the vehicle.
The technical field of the invention is that of repairing motor vehicle bodywork.
It is known to protect the windows of a motor vehicle prior to painting at least a portion of its bodywork by means of masks that cover said windows. The term “window” is used essentially to cover the non-painted portions of the vehicle, in particular the windshields, the back window, the left and right side windows, the headlight units, the rear light units, the outside mirrors, and other parts such as wheels, hubcaps, or bumpers.
To perform this masking operation, also known as “papering”, it is common practice to use paper dispensed from a roll; for each member that needs to be protected, the operator cuts and/or tears a sheet of paper by hand; the width of the sheet is the width of the selected roll of paper, and the length of the sheet is determined approximately by the operator as a function of the dimensions of the member that is to be protected; the sheet thus presents two first edges that are parallel and rectilinear, and two second edges that are of a shape and orientation that are the result of the cutting technique used; under no circumstances does the shape of the sheet as formed in this way correspond to the shape of the member that is to be protected; the operator needs subsequently to tear and/or crumple the sheet so as to match its outline approximately to that of the member that is to be protected; these operations are lengthy and difficult, and the resulting sheet never matches exactly the shape of the part that is to be protected.
In the construction industry, U.S. Pat. No. 3,752,304 discloses the idea which consists in using triangular masks for covering a rectangular glazed area of a window by means of two adjacent masks that overlap; pairs of identical masks are grouped together to form rectangles; the masks make up a roll provided with transverse perforations in order to enable rectangular sheets to be prepared manually; that document gives no indication about the appropriate sheet material.
In the automobile industry, it is known to use masks of shape matching the shape of a portion of a vehicle in order to protect said portion during an operation of painting some other portion of the vehicle.
U.S. Pat. No. 2,371,859 describes a flexible masking device which is constituted by a strip of rubber and a flexible cloth covering which is spread over the portion of bodywork that is to be protected, being fixed to and suspended from the strip of rubber; that strip is sufficiently flexible to be applied to surfaces that present corners and irregular outlines; it has a series of cavities forming suction cups to enable the strip to be secured to the bodywork by suction so that no adhesive is needed. Although that devices presents advantages, it is not adapted to enabling a window portion of a motor vehicle to be masked quickly and accurately at low cost.
Document EP 0 334 360 describes multilayer structures for masking a portion of the bottom face of a vehicle, the structures comprising a layer of plastics material foam, a layer of adhesive coating one face of the layer of foam, and a peel-off protective sheet covering the layer of adhesive; discontinuous lines of cut constituted by grooves or perforations are provided so as to enable a portion of said structure to be cut off manually so as to form a mask constituted by one or more individual masks each defined by said lines. It will be understood that such a system makes it possible to obtain a mask presenting a shape that matches very approximately the shape of a portion of a vehicle that needs to be protected; such a structure is capable of being fitted properly only to a portion of a vehicle whose shape matches that of an individual mask or a plurality of juxtaposed individual masks; such a sheet therefore does not make it possible to match accurately the outline of a window portion of a vehicle.
An object of the invention is to provide papering masks, their method of manufacture, and their method of use, which are improved and which remedy, at least in part, the drawbacks of known papering methods and devices.